Since 1965 there have only been three hereditary peerages created for non-royals. Two of these are already extinct.
In 1983, Willie Whitelaw was created Viscount Whitelaw. He had no sons (although he did have four daughters) and so the peerage became extinct upon his death.
Also in 1983, George Thomas was created Viscount Tonypandy. The title was a bit of a joke: it had been his nickname since his youth. He had no children (he was gay, although he fought a losing battle to keep it secret all his life) and the title also became extinct upon his death.
And in 1984 Harold Macmillan was made Earl of Stockton and Viscount Macmillan. His titles were inherited by his grandson, who now holds them.